I am new to archery, in fact i'm new to hunting. I purchased a bow 3 weeks ago and have been shooting just about every day. I finally have it where i'm shooting good groups at 20 yards with 100g field tips. I bought Muzzy 3 blade 100g broadheads and tried them. They are less consistant and shoot about 4 inches to the left of the bull. Is this normal? Not sure if it matters but I am shooting a Whisper Biscuit rest.